The present invention relates to synchronous reluctance motors and generators having a simple and maintenance-free construction which can be widely used in various industrial fields. Although the present invention includes not only motors, but also generators, the following explanation will be focused on the motors, because motors are far more widely used than generators.
Reluctance motors with a simple rotor construction having no winding thereon have the merits of being maintenance-free and, moreover, have a high efficiency because no copper loss is generated in the rotor. However, reluctance motors generate pulsating torques due to the harmonic components contained in the air-gap flux, and these harmonic flux densities also produce additional core losses which reduce the efficiency.
Therefore, it is a most important problem in reluctance motors and generators in how to decrease the pulsating torques and harmonic core losses. The object of the present invention is to provide inexpensive and maintenance-free reluctance motors and generators which can be driven with high efficiency and good stability by solving the problems stated above.